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Biomedical subjects

Yan Zhang

Publications and source records attributed to Yan Zhang.

At least 163 records · Page 9Linked to original sources
PubMed2006

[Genotype of wild-type measles viruses circulating in Beijing in 2003].

OBJECTIVE: To investigate genotype of wild-type measles viruses circulated in Beijing in 2003. METHODS: Throat swabs specimens were collected from patients seen during an outbreak of measles and from clinically suspected sporadic measles patients in 2003. Vero/SLAM cell lines recommended by WHO were used to isolate measles virus. Four hundreds and fifty nucleotides of COOH-terminal of nucleoprotein (N) genes were amplified by using PR-PCR. The amplified products were sequenced and the sequences were compared with references viruses from GeneBank. RESULTS: Eight strains of measles viruses were isolated from throat swabs of patients who came from seven districts and counties of Beijing. Sequence analysis of the 450 nucleotides of COOH-terminal of nucleoprotein (N) genes indicated that these 8 strains belonged to H1a genotype. The average genetic distances of these 8 strains to H1a genotype, Chin9322, H1b genotype, Chin9475 and H1c genotype, Chin9427, were 0.004 - 0.011, 0.026 - 0.031 and 0.015 - 0.022, respectively. The average genetic distances of these 8 strains to H1a genotype, Anhui 01 - 1/Anhui 02 - 2, were 0.000 - 0.009 (0 - 5 nucleotide variation). CONCLUSIONS: Major genotypes of wild-type measles viruses circulated in Beijing in 2003 were H1a genotype. The genotypes H1c, H1b and H2 may have disappeared in Beijing.

Child↗
PubMed2006

[Application of fluorescence in-situ hybridization and reverse transcription-polymerase chain reaction in molecular diagnosis of Ewing's sarcoma and primitive neuroectodermal tumor].

OBJECTIVE: To detect tumor specific chromosome translocations and associated fusion transcripts in paraffin-embedded tissue by interphase fluorescence in-situ hybridization (FISH) and reverse transcription polymerase chain reaction (RT-PCR), respectively, and to evaluate their diagnostic values for Ewing's sarcoma/primitive neuroectodermal tumor (ES/PNET). METHODS: Nuclei of the tumor cells and total RNA were extracted from 10 cases of ES/PNET. Interphase FISH was utilized to analyze the EWS gene translocation with a dual color, break apart probe (Vysis company). RT-PCR was used to detect t (11; 22) (q24; q12) and t (21; 22) (q22; q12) fusion transcripts. RESULTS: Among 10 cases of ES/PNET, the EWS-FLI1 fusion transcript was detected in 8 by RT-PCR. EWS-ERG fusion transcript was not detected in any of the cases. EWS gene translocation was found in 9 of 10 cases by FISH. CONCLUSIONS: Interphase FISH and RT-PCR can be reliably applied to paraffin-embedded tissues for molecular diagnosis of ES/PNET. Between the two approaches, interphase FISH provides a more sensitive and stable result.

Adolescent↗
PubMed2006

[The effects of ezrin on the proliferation and the invasiveness of cells of different hepatocellular carcinoma cell lines].

OBJECTIVE: To investigate the different expressions of cytoskeletal organizer ezrin and cytoskeleton protein beta- and gamma-actin in hepatocellular carcinoma (HCC) cell lines with different metastatic potentials and to explore the role of ezrin in cell growth and metastasis in HCC cell lines SF7721 and MHCC97-H. METHODS: Immunofluorescence, RT-PCR and Western blot were used to detect the gene and protein expressions of ezrin and actin in hepatocellular carcinoma cell lines with different metastatic potentials. RNA interference (RNAi) was applied to down-regulate the ezrin expression in SF7721 and MHCC97-H. Changes of the cell growth and metastasis potentials after the RNAi treatment were studied. MTT assay was used to detect cell proliferation changes and Transwell assay was applied to observe the changes of cell motility and invasiveness. RESULTS: Both ezrin and cytoskeleton protein were demonstrated in the cytoplasma of the cells at the same time. The expression of them in cell lines with high metastatic potential, such as SF7721, MHCC-1 and MHCC97-H was obviously higher than in those with low metastatic potentials, such as SMMC-7721, Hep3B and HepG2 (chi2= 13.277, P = 0.010; chi2= 21.815). The mRNA and ezrin and cytoskeleton protein gamma-actin were over-expressed in HCC cell lines with high metastatic potentials. The expressions of beta-actin of cell lines with different metastatic potentials showed no differences. Ezrin protein was successfully down-regulated and the proliferation and the invasiveness of the cells decreased with low ezrin protein level in SF7721 and MHCC97-H. CONCLUSION: Over-expression of ezrin and cytoskeleton protein gamma-actin are associated with the process of metastasis of hepatocellular carcinoma cells. The growth and invasiveness of SF7721 and MHCC97-H cells can be inhibited by down-regulating ezrin expression.

Actins↗
PubMed2006

[Preliminary study on a new sentinel lymphoscintigraphy agent 99mTc-Rituximab for breast patient].

OBJECTIVE: To develop a new imaging agent, (99m)Tc-Rituximab, for sentinel lymphoscinti-graphy and investigate its feasibility in detecting the sentinel lymph node (SLN) for breast cancer patient. METHODS: (99m)Tc-Rituximab was prepared by introducing (99m)Tc directly into the mclecule of Rituximab, thus a new kind of lymphoscintigraphy agent ((99m)Tc-Rituximab) was produced. Five Bal b/c mice and ten breast cancer patients underwent dynamic SLN mapping procedures using (99m)Tc-Rituximab. Axillary lymph node status in breast cancer patients were evaluated with the fusion images, which was processed by computer software. With ROI technique, SLN/background ratio and the rate of SLN uptake were calculated and the dynamic curve of SLN uptake was drawn. The other 61 breast carcinoma patients underwent routine lymphatic mapping. Sentinel lymph node biopsy (SLNB) and axillary lymph node dissection (ALND) were both performed in all 71 patients. Fresh SLNs and all axillary nodes were sent for pathological examination using hematoxylin and eosin (H&E) staining. RESULTS: (99m)Tc-Rituximab, with a yield of about 95.0%, can show SLN status in both mice and patients. The fusion image showed SLNs clearly, even the depth of SLNs in the axilla. The results of dynamic SLN mapping showed visible SLN starting from 10 min, up to 16 h after injecting tracer, however, secondary lymph nodes were not detectable at all. In mice, the ratio of SLN/background was 2.1, the rate of uptake was about 3.0% to 3.5%, and the equation of the curve was produced as: y = 0.036x + 2.7875, r(2) = 0.9787. For breast cancer patients, the uptake rate was different from case to case, but the cure seemed to be consistent with logarithm. The result of SLNB and ALND showed that the sensitivity and accuracy of SLNB was both 100.0%. The average number of SLNs found in each case was 2.6. Of nineteen breast cancer patients (26.8%) with lymph node metastasis, 11 were found to only have SLN metastasis. CONCLUSION: (99m)Tc-Rituximab, as a new tracer to mapping sentinel lymph node for breast cancer patient, is able to show the status of sentinel lymph node reliably. The fusing image is easy to obtain and be interpreted by the clinician.

Adult↗
PubMed2006

[Discussion on reinforcing-reducing method by lifting and thrusting the needle and slow-rapid reinforcing-reducing method from the point of view of energy].

OBJECTIVE: To resolve the contradictory in expounding of reinforcing and reducing by lifting and thrustion the needle and slow-rapid reinforcing and reducing method. METHODS: In a certain condition,the relationship between the external force (the joint force of both the pressing on the force pressing on the needle and the force arresting the needle's moving) and the speed of needle's moving is deduced by means of kinetic energy theorem, so, when the needle is heavily thrust or lifted, the speed of its moving will be increased. CONCLUSION: In the reinforcing and reducing method by lifting and thrusting the needle, "heavily"and "gently" of heavily thrustiing and gently lifting or gently thrusting and heavily lifting should be considered as differences of the amplitudes of lifting and thrusting the needle; "slow-rapid" of slow-rapid reinforcing and reducing method should be considered as difference of the speeds.

Acupuncture Therapy↗
PubMed2006

[Expression of Smad4 in leukemia cells].

Loss of transforming growth factor (TGF)-beta signaling has been implicated in malignant transformation of various tissues. Smad4 plays a central role in the signal transduction of TGF-beta. Deletion or mutation of Smad4 has been described in a number of cancers. This study was aimed to investigate a potential role of Smad4 in leukemia including its expression and location in blast cells. The mononuclear cells were separated from bone marrow of leukemia patients. The samples, blast cells of which were more than 90% in mononuclear cells, were selected. The expression and location of Smad4 protein were analyzed by immunohistochemistry methods. The results showed that the Smad4 protein located mainly in nucleus, part of this protein located in cytoplasma, the expressions of Smad4 were not detected in 6 out of 9 ALL patients, in 7 out of 24 AML patients and in 1 out of 2 CML patients; these leukemia patients, in whose cells the expression of Smad4 was not detected, included one L1 and one L3, four L2, one M0, one M1, two M2a, one M3a, one M4b, one M6 and one CML. In conclusion, the Smad4 protein was mainly in nucleus, the deletion or functional change of Smad4 may related with the pathogenesis of human AML.

Humans↗
PubMed2006

[Preparation and characterization of anti-Drosophila Dnop5 antibody].

AIM: To prepare the rabbit antibody against Dnop5 and identify its specificity. METHODS: Dnop5 cDNA was amplified by RT-PCR, and then was subcloned into the fusion expression vectors pET28a(+). After being expressed in E.coli BL21, the truncated Dnop5 protein was purified and used to immunize rabbit. Purified antibody was obtained through affinity chromatography column with the expressed Dnop5. The specificity of the purified antibody was characterized by Western blot and immunohistochemical staining. RESULTS: The Dnop5 gene was successfully inserted into pET28a(+). After induction, the fusion protein was expressed in the form of inclusion body. The purified fusion protein was obtained by affinity chromatography. After immunization of rabbits, the antibody against Dnop5 was obtained. Western blot analysis and immunohistochemical staining showed that the antibody had a good specificity. CONCLUSION: The rabbit antibody against Dnop5 has been successfully prepared, which lays the foundation for further study on the Dnop5 function.

Animals↗
PubMed2006

Effect of sodium hydroxybutyrate on the expression of hippocampal N-methyl-D-aspartate receptor 2B subunit mRNA in neonatal rats with hypoxic-ischemic insult.

The objective of this research was to test whether sodium hydroxybutyrate (GHB-Na) protects rat neonatal brain against hypoxia-ischemia (HI). Specifically, the objective was to determine the effect of GHB-Na administration on the expression of N-methyl-D-aspartate subunit (NR2B) mRNA in the rat hippocampus. Seven-day-old Sprague-Dawley rats were subjected to ligation of the left carotid artery and were randomly assigned to 5 groups: sham operated (S), saline treated (C), and those treated with GHB-Na (G1, G2, G3), at 3 dosages (50, 100, or 200 mg/kg, ip, thrice daily). NR2B mRNA levels in the left hippocampus were assayed at 2, 6, 12, 24, 72, and 168 hr after HI (exposure to 8% O(2)/92% N atmosphere for 2 hr). The results suggest that HI insult increased NR2B mRNA gene expression in the left hippocampus of the neonatal rats and that GHB-Na administration partially suppressed this effect of HI insult.

Animals↗
PubMed2006

[Mnemonic strategy for english vocabulary of TCM fundamental theory formed by borrowing translation and morphemic translation from Western medical terms].

In the article, the importance and feasibility of borrowing translation and morphemic translation from Western medical terms for translating terms of TCM fundamental theory are briefly reviewed, and mnemonic strategy for the memorization of TCM vocabulary formed by the two translation methods is discussed.

Medicine, Chinese Traditional↗
PubMed2006

[Effects of exposure to extremely low frequency electromagnetic fields on reproduction of female mice and development of offsprings].

OBJECTIVE: To observe the effects of exposure to extremely low frequency electromagnetic fields (ELF EMFs) on pregnant mice and development of offsprings. METHODS: Female mice were exposed to 50 Hz, 1.2 mT electromagnetic fields during the whole pregnant period (8 h/d). The body weight of dams, delivery and development of offsprings were observed and measured. RESULTS: The increase of body weight of exposed dams (29.0%) was significantly slower than that of the control group (47.8%) during late pregnancy period (P < 0.05). The producing rate of exposed group was 60% of that of control group. Miscarriage, fetal loss and externally malformed fetus appeared in exposed group. The average number of offsprings of each exposed mouse was significantly decreased (11 +/- 1.6 vs 7 +/- 2.0, P < 0.05) and 11 for control group. Regarding the development of offspring, the body weight of prenatally exposed offsprings was increased more slowly than that of the control in the first two weeks after birth (P < 0.05). Developmental manifestations including eye opening [(252 +/- 24) h] and tooth eruption [(336 +/- 19) h] presented later in exposed offspring [(226 +/- 12), (319 +/- 15) h, respectively] (P < 0.05). CONCLUSION: Exposure to ELF EMFs during pregnancy period can cause adverse effects on pregnancy of female mice and development of offsprings.

Abnormalities, Radiation-Induced↗
PubMed2006

[Optimization of high performance liquid chromatographic method for analysis of kudzu root crude extract].

Kudzu root is an important traditional Chinese herb. Its crude extract has been used in the treatment of hypertension and angina pectoris in China. Several parameters for high performance liquid chromatography (HPLC) analytical method for kudzu root extract, including HPLC model, mobile phase, additive and gradient conditions have been optimized. The HPLC retention parameters a and c, and the peak shape parameters sigma and tau of 25 chromatographic peaks were obtained accurately and rapidly using five linear gradients and were calculated using CSASS software. The CSASS software was then used to simulate the gradient conditions in the experiments, and the optimized condition was obtained. The comparison of the simulated and real chromatogram profiles showed that the potential of simulation using the CSSASS software as compared to that of the real experimental conditions was precise. Reversed-phase HPLC model and the mobile phase of (A) acetonitrile containing 0.1% (v/v) acetic acid and (B) water containing 0.1% (v/v) acetic acid were used. The optimized gradient profile showed a linear increase as follows: from 5% A to 35% A at 0 - 33 min; from 35% A to 100% A at 33 - 50 min, and then the HPLC system was held for 5 min. The reproducibility and precision of the method were investigated. The relative standard deviations (RSDs) of retention time, peak height, and peak area were less than 0.25%, 11%, and 4.9%, respectively, which showed that the method was stable, reliable, and reproducible.

Chromatography, High Pressure Liquid↗
PubMed2006

[Orthogonal experiments on cultivation of Phyllanthus urinaria].

OBJECTIVE: To study the growth rules, the output and the influence factors of cultivated Phyllanthus urinaria, and provide basis for standardized cultivation. METHOD: Orthogonally designed field experiments with three factors and three levels, comparing the characters of cultivated plants and the wild ones of P. urinaria. RESULT AND CONCLUSION: Under the manual planter condition, the characters, such as branching number, single dry weight, single output etc, enhanced enormously, and the increase of single output reaches 3.27 times. The sowing time was the most sensitive factor, which affected the single character and the yield per unit of area, whereas the different levels of sowing thickness and fertilizer also remarkably influenced the output. When the seeds were sowed at the mid-April earlier period, drilling with the 20 cm row spacing, they started to emerge about 1 week later, the growth flush period was from June to August, the growth slowed down in September, and the output per hectare could reach to 5.750 kilograms at harvest in late October.

Fertilizers↗
PubMed2006

[Liuweidihuang pills reduces visceral fat deposition in Otsuka Long-Evans Tokushima Fatty rats].

OBJECTIVE: To investigate the effects of Liuweidihuang pills (LP) on visceral fat deposition in Otsuka Long-Evans Tokushima Fatty (OLETF) rats. METHODS: Forty male OLETF rats were randomly divided into LP group and control group (n=20 per group), and 10 male Long-evans Tokushima Otsuka (LETO) rats were used as normal controls. The rats in LP group were given LP(2.4 mg/kg) daily by intragastric administration since the age of 8 weeks, and those in the other two groups were given water of the same volume by intragastric administration. Blood glucose of all the rats was determined by oral glucose tolerance test (OGTT) and visceral fat deposition examined after the rats were sacrificed. RESULTS: OLETF rats had obviously greater amount of visceral fat than LETO rats (P<0.05) and administration of LP ameliorated the increment of visceral fat deposition in this type 2 diabetic model, producing significant effect at the age of 40 weeks (P<0.01). CONCLUSION: LP may effectively decrease visceral fat deposition in OLETF rats.

Animals↗
PubMed2006

[Effects of beta1-integrin, fibronectin and laminin on invasive behavior of human gliomas].

OBJECTIVE: To investigate the effects of beta1-integrin, fibronectin (FN) and laminin (LN) on the invasive behavior of human gliomas. METHODS: Functional impacts of beta1-integrin, fibronectin and laminin on cell adhesion, migration and metastasis of U251 malignant glioblastoma cells were investigated by in vitro adhesion, migration and invasion assays. The amount and distributions of cellular microfilaments and pseudopodia were studied by fluorescent cytochemistry, confocal laser scanning microscope and scanning electron microscope. Lastly, beta1-integrin, fibronectin and laminin were investigated for their roles in cellular microfilament skeleton. RESULTS: (1) Fibronectin did not affect cell adhesion of U251MG cells, but anti-beta1 integrin antibodies inhibited cell adhesion (P < 0.01); Laminin stimulated cell adhesion of U251MG cells (P < 0.01) but anti-beta1 integrin antibodies had little effect on the laminin-mediated cell adhesion. (2) The migration of U251MG cells on dishes coated with FN was inhibited by anti-beta1 integrin antibodies (P < 0.05). (3) F-actins formed strong and dense stress fibers in U251MG cells on dishes coated with FN and LN. Anti-beta1 integrin antibodies disrupted the microfilament network and F-actin aggregation. (4) FN and LN increased the number of pseudopodia on cell surface, whereas anti-beta1 integrin antibodies reversed this function. (5) FN and anti-beta1 integrin antibodies had little effects on the invasive ability of U251MG cells in vitro. The invasion was increased by LN, but inhibited by anti-beta1 integrin antibodies. CONCLUSIONS: (1) The interaction between beta1-integrin, FN may stimulate U251MG cell migration via changing the structures of microfilament skeleton and the number of pseudopodia. (2) beta1-integrin may play a role in the LN-mediated in vitro invasion of U251MG cells.

Cell Adhesion↗
PubMed2006

[The Chinese registry on reperfusion strategies and outcomes in ST-elevation myocardial infarction].

OBJECTIVE: To analyze the current use of reperfusion strategies and the outcomes of patients with ST elevation acute coronary syndromes (ACS) in China. METHODS: A total of 518 consecutive patients (371 male and 147 females, mean age 65 +/- 11) with ST elevation ACS or newly discovered left bundle branch block were registered from 20 hospitals from 5 regions (ranging from large regional centre hospitals to small county hospitals) in China. Patient general characteristics, reperfusion patterns and outcomes were analyzed. Patients were followed up for 3 months. RESULTS: The median time from pain onset to presentation at the hospital was 4 hours. Pre-hospital delay > 12 hours was found in 20% patients. Fifty-six percent patients (292/518) underwent reperfusion therapy (134 with primary percutaneous coronary intervention and 158 with fibrinolysis). The median time from admission to reperfusion (door-to-needle) was 65 min in fibrinolysis group and 110 min (door-to-cath) in primary PCI group respectively. Urokinase was used in 67% (106/158) patients underwent fibrinolysis. Multivariate logistic regression analysis showed that age >/= 75 years (P < 0.01), previous myocardial infarction (P < 0.01) and history of congestive heart failure (P < 0.05) were associated with no reperfusion therapy. Mortality and congestive heart failure rates were significantly higher in patients with no reperfusion therapy not only at discharge (P < 0.01) but also at 3 months (P < 0.01) compared to patients underwent reperfusion. The incidence of combined outcomes (death or MI, and death, MI or Strobe) was also higher in patients without reperfusion therapy at 3 months (all P < 0.01) compared to patients underwent reperfusion. There were no differences on combined outcomes between fibrinolysis and primary PCI subgroups. CONCLUSION: Reperfusion therapy was the primary treatment of choice to improve the outcomes of patients with ST elevation ACS. Strategies to increase reperfusion therapy rate for ST elevation ACS are urgently needed in China.

Aged↗
PubMed2006

[Ischemic postconditioning attenuates ischemia/reperfusion injury in isolated hypertrophied rat heart].

OBJECTIVE: To explore the effects of ischemic postconditioning on ischemia/reperfusion injury in isolated hypertrophied rat heart and investigate the signal transduction pathway changes induced by ischemia postconditioning. METHODS: Cardiac hypertrophy was induced in rats by abdominal aortic banding, and isolated hypertrophied rat heart ischemia/reperfusion model was made by Langendorff technique to evaluate the effects of ischemia postconditioning on left ventricular systole pressure, coronary artery flow, creatine phosphokinase (CPK) and lactate dehydrogenase (LDH) release, myocardial infarction size, and the level of myocardial phospho-protein kinase B/Akt (Ser473), phospho-glycogen synthase kinase-3beta (Ser9). Following groups were studied (n = 12 each group): IR, 30 min ischemia (I)/60 min Reperfusion (R); Post: 30 min ischemia, 6 circles of 10 s I/10 s R followed by 60 min R; Post Wort: 30 min ischemia, 6 circles of 10 s I/10 s R, wortmannin (10(-7) mol/L) followed by 60 min R; Wort: 30 min ischemia, wortmannin (10(-7) mol/L) followed by 60 min R. RESULTS: Left ventricular systolic pressure and coronary artery flow were significantly increased, myocardial infarction size and the release of CPK, LDH significantly reduced in Post group compared to that in IR group. Phospho-protein kinase B/Akt (Ser473) and phospho-glycogen synthase kinase-3beta (Ser9) levels were also significantly higher in Post group than that in IR group. Phosphatidylinositol 3-kinase (PI3K) inhibitor wortmannin prevented the increase of phospho-protein kinase B/Akt (Ser473) and phospho-glycogen synthase kinase-3beta (Ser9) induced by ischemic postconditioning, but only partly abolished the cardioprotection of ischemic postconditioning. CONCLUSION: Ischemic postconditioning attenuates ischemia/reperfusion injury in isolated hypertrophied rat heart. The cardioprotective effects of ischemic postconditioning were partly mediated through PI3K/Akt/GSK-3beta signaling pathway.

Animals↗